The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Historically, the standard method of sealing two joints not directly connected to each other has been to use a tube with an o-ring at each end. This design has been found to have two main deficiencies; the first being the seal's inability to compensate for offset between the two bores and the second being various assembly issues including missing o-rings, cut o-rings, rolled o-rings and overall labor intensive.
An improvement to this sealing solution was patented in Europe (DE19548249C2 and DE19902953A1) by FDS Reichelsheim by directly molding rubber to an adhesive covered tube. This technique allowed for large seal beads to be incorporated into the design which would allow for misalignment in the application as well elimination of the majority of assembly issues found with the tube and o-ring design. The deficiency with this design is the reliance on the adhesive bond between the tube and the rubber which has the bond failure modes already specified.
Current design tube seals are 100 percent reliant on rubber to metal adhesion for proper function. Adhesive to metal bond failure has resulted in field failures of tube seals utilizing straight wall designs. Several failure modes have been found to cause this condition including initial metal surface condition, inadequate metal preparation, adhesive thickness, adhesive age, adhesive “sweep” during molding and mold release “sweep” during molding. Adhesive “sweep” is caused by the injection of rubber into the mold that flows parallel to the wall of the tube and “sweeps” away the adhesive that is applied to the wall so that the adhesive is pushed toward the bottom of the seal.
The present disclosure provides a tube seal, comprising: a rigid cylindrical tube including a recessed annular groove provided in an outer surface thereof at each end of the cylindrical tube; and an elastomeric seal body molded to the outer surface of the cylindrical tube so as to be received in the recessed grooves, the seal body including a raised seal bead portion at each end of the seal body. The elastomeric material received in the recessed grooves of the rigid tube removes the reliance solely on rubber adhesion to achieve acceptable seal performance and still retains the benefits of an over-molded tube seal design.
The mechanical bead lock feature incorporated into the supporting insert results in an elastomer ring that provides sufficient interference with the insert to allow for proper installation of the seal into the application with no adhesive bond between the insert and elastomer required. The mechanical bead lock feature also results in sufficient elastomer compression to provide adequate sealing in the application with no adhesive bond between the insert and elastomer required.
The present disclosure also provides a diameter reducing tube seal that connects a larger bore to a smaller bore and incorporates an inner diameter which transitions from a smaller diameter to a larger diameter. The transition is in such a manner as to minimize the effect on pressure and flow of the media passing through the seal regardless of flow direction. In particular, the disclosure includes a diameter reducing tube seal, comprising: a generally conically shaped rigid insert having a first opening at a first end and a second opening at a second end, said first opening being larger in diameter than said second opening; and an elastomeric seal body molded to said rigid insert and including annular raised bead portions surrounding each of said first and second openings.
The present disclosure also incorporates an integrated filter device in a tube seal according to the present disclosure. In particular, the present disclosure provides a tube seal and integrated filter, comprising: a rigid cylindrical tube having a first opening at a first end and a second opening at a second end thereof; an elastomeric seal body is molded to the outer surface of the cylindrical tube, the seal body including a raised seal bead portion at each end of the seal body; and a filter member disposed in the rigid cylindrical tube.
The present disclosure also incorporates a valve structure molded inside of a tube seal for providing directional or pressure control of the media passing through the seal. In particular, the present disclosure includes a tube seal, comprising: a rigid cylindrical tube having a first opening at a first end and a second opening at a second end thereof; an elastomeric seal body is molded to the outer surface of the cylindrical tube, the seal body including a raised seal bead portion at each end of the seal body; and an elastomeric duck-bill valve molded inside of the rigid cylindrical tube.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.